The invention relates to dental adhesive compositions for bonding dental restoratives to dentin and enamel. More specifically the invention provides a one-part self-etching, self-priming dental adhesive composition comprising hydrolysis stable polymerizable acidic adhesive monomers.
Presently, self-etching, self-priming dental adhesives are composed of two-part systems due to stability issues of the polymerizable acidic monomers The stability issues are due to the hydrolysis of acidic and adhesive monomers in water or water/solvent mixtures. Therefore the acidic and adhesive monomers are stored water-free and mixed with the aqueous part just before application
Frequently, sulfuric acid ester or phosphorous ester groups are employed in acidic polymerizable adhesive monomers. These acidic groups tend to hydrolyze ester moieties within of the monomers. To overcome these disadvantages polymerizable phosphonic esters were proposed (DE 19918974). However, these monomers still comprise hydrolysable (meth)acrylic ester moieties. Recently, hydrolysis stable monomers with phosphonic acid ester groups based on a-(oxo ethyl) acrylate were claimed (DE 19746708). However, the synthesis of these monomers is rather expensive and cost prohibitive for the envisaged applications.
Two-part self-etching, self-priming dental adhesive systems are either applied sequentially or in one step after mixing the two parts. Both procedures have inherent disadvantages due to clinical complications which might occur inbetween sequential steps (saliva or blood contamination) or due to dosing problems when mixing is required prior to the application of the self-etching adhesive.
In order to overcome these clinical problems it would be advantageous to provide the self-etching adhesive as a one-part system eliminating the need of sequential application or premixing.